1. Field of the Invention:
This invention relates to a method of applying injection-molded end stop members to slide fasteners and an apparatus for carrying this method into practice.
2. Description of the Prior Art:
Fluidtight, i.e. airtight or watertight, slide fasteners are known, as the name implies, for their capability of sealing against leakage under various enviromental conditions. The seal is effected along confronting longitudinal edges of two opposed stringer tapes when they are brought into abutting relation to each other by a slider member. To this end, the longitudinal tape edge is beaded or folded on one side upon which is mounted a row of coupling elements typically of a discrete formation, each element being covered by a sealing strip. The folded tape edge must be spaced a sufficient distance apart from the upper surface of the tape web such that the slider can move smoothly along and couple or uncouple the opposed fastener stringers. Therefore, the tape edges are, particularly in uncoupled condition, unstably movable with respect to the plane of the fastener, but are required in coupled condition to assume substantially upright position. When applying end stops as by injection-molding to such tape edges at the top or bottom end portion of the tape, care must be taken so that the lengths of the tape edges to which the end stops are applied maintain such upright position throughout the injection-molding operation to ensure alignment with ensuing contiguous lengths of exposed tape edges. Failing this would result in warped or displaced coupling elements that neighbor the end stops, thus eventuating in a malfunctioned or defective slide fastener.